Ferdinand polster



(No Model.)

F. POLSTER.

UPRIGHT PIANO ACTION. No. 314,195. Patented Mar. 17, 1885.

Will/WWW UNITED STATES PATENT Orrrca.

FERDINAND POLSTER, OF BALTIMORE, MARYLAND, ASSIGNOR TO IVM. KNABE & OO.,OF SAME PLACE.

UPRlGHT-PIANO ACTION.

SPECIFICATION forming part of Letters Patent No. 314,195, dated March17, 1885. Application filed April 14, 1884. (No model.)

To all whom, it may concern.-

Be it known that I, FERDINAND PoLsrEn, of Baltimore, in the county ofBaltimore and State of Maryland, have invented certain new and usefulImprovements in Upright-Piano Actions; and I do hereby declare thefollowing to be afull, clear, and exact description of the inventionsuch as will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to improvements in repeatingactions for uprightpianos; and it consists partly in a novel construction and arrangementof the hammer-butt and back check; secondly, in the peculiarconstruction of the jack which operates in connection with thehammer-butt and back-check; thirdly, in

the arrangement of an auxiliary spring-jack having both a longitudinaland lateral movement.

It consists, finally, in details of construction and arrangement fullyhereinafter explained.

The drawing shows a side elevation of a portion of a piano-action, thehammer-rail, sounding-board, and ham mer-rest being shown in section.

A represents one of the key-levers of an upright piano-forte.

B is the lifter connected to the inner end of the key, and bearing onthe lower surface of the fly-lever O, the latter being pivoted on ahanger secured to the hammer-rail D.

A double-forked standard, a, is secured to the hammer-rail, at one endof which is pivoted the hammer-butt E, and at the other the damper E Thehammer E is operated by the jack or fly G, pivoted to the lily-lever O.The uppcr end of the jack bears against the hammer-butt and operates thehammer in the usual manner. H is the hammer-rest, and I the sounding-board.

A back-cheek, J, is adjustably secured to the butt E by means of ascrew-rod, e. The surface against which the jack bears is inclined, asshown, and suitably deadened. At the upper end of the jack is an angularprojection, f, the inclined side of which is adapted to fit closelyagainst the corresponding incline of the back-cheek when the key isdepressed. firmly against the butt as the hammer is in the act ofstriking the string. The movement of the jack may therefore be easilylimited or increased by proper adjustment of the backcheck.

K represents an auxiliary jack connected to the main jack G, but havinga motion independently thereof. A sliding screw-tln'eaded rod, k, has ahead, k, which rests against the head ofjack G, and, like it, bears onthe hammer. This rod passes through perforated brackets Z Z on the jack,and a bracket, Z on the hammer-rail. The movement of the rod L islimited by a pair of check-nuts, m m, one of which works on the rodbelow the bracket Z, the other below the bracket Z, a spiralpressure-spring being mounted on the rod between the bracket Z and abutton, a, which regulates its pressure. \Vhen the key is depressed andthe jack G is raised, the rod It moves with it a distance limited by theposition of the nut m, and as the head It bears on the butt suchmovement tends to raise the hammer. XVhen the projection on the jackbears on the inclined face of the back-check, the head it is broughtdirectly beneath the butt. WVhen the key is released, the pressurespring tends to throw thejack downward.

The auxiliary jack is prevented from moving by turning the nut m up tobear against the bracket Z".

Having fully described my invention, "what I claim as new, and desire tosecure by Letters Patent, is-

1. In a piano-action, the combination, with a hammer and hammer-butt, ofa back-check, a pivoted jack, and an auxiliaryjack having a movementindependently of the pivoted jack, substantially as set forth.

2. In a piano-action, the combination, with a hammer-butt and adjustableback-check, of a pivoted jack and a spring-actuated auxiliary jackconnected to the main jack, but having a motion independently thereof.

3. In a piano-action, the combination, with a hammer, hammer-butt, andan adjustable back-check having an inclined face, of the The oppositeedge of the jack bears In testimonywhereof I have signed thisspecification in the presence of two subscrib-- IO ing witnesses.

pivoted jack having an angular projection, and the auxiliaryjaekconnected to said pivoted jack, but having a motion independentlythereof, substantially as set forth.

5 4. The combination, with the jack G and hammer, of the sliding rod 7:,the spring, and the adjustable check-nuts, substantially as described.

FERDINAND POLSTER.

Witnesses:

BATZLER, En. RAINE.

